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Area forecast discussion 
National Weather Service Des Moines Iowa
332 PM CDT Wednesday may 27 2015

Short term /tonight/...
issued at 332 PM CDT Wednesday may 27 2015

Quiet night tonight weather-wise. Upper level ridging gradually
shifts east with the ridge axis from roughly Mason City to
Burlington by 12z Thursday. Surface high pressure will also shift
to the east bringing return flow to at least western Iowa by
Thursday morning. Between 09z and 12z a weak shortwave will enter
western Iowa and some rather impressive warm advection will be
ongoing. Some weak forcing and Theta-E advection will occur across
western into southern Iowa and this may aid in producing some
showers and thunderstorms towards the very end of the period.
However the better forcing and Theta-E advection will occur closer
to a deepening surface low occurring on the Lee side of The Rockies.
Hi-res models seems to want to develop storms initially then fizzle
them out towards middle morning Thursday. I did put slight chance probability of precipitation
across the far southwest/south towards 12z and this may be underdone
but the 18z NAM came in closer to what the hi-res models had been
indicating earlier so I felt higher probability of precipitation were not warranted at this

Long term /Thursday through Wednesday/...
issued at 332 PM CDT Wednesday may 27 2015

Southwest upper flow develops on Thursday as upper ridge passes
tonight. Will see the return of southerly flow and increasing
Theta-E advection during the day. Showers and a few storms are
expected with this slowly advancing area of moisture advection
during the day...gradually from west to east. The moisture
transport will remain strong into Thursday night and focus ahead
of advancing boundary with thunderstorms expected...mainly in the
north and west overnight...although some will spill into the south
and east as forcing increases. Forcing and moisture transport into
the boundary will continue into Friday as the boundary slides
across the state. Anticipate the precipitation to persist along
and ahead of the boundary during the day...while gradually ending
from northwest to southeast as the front pushes southeast. At this
point...the severe weather threat seems limited as shear profile
is generally quite weak. Anticipate any severe storms to be short
in duration and somewhat marginal. Quantitative precipitation forecast will generally be from one
half inch to an inch and a half across the state with some
isolated higher amounts which will keep rivers running well but no
large flooding issues are anticipated at this time.

The front will blow through on Friday night with any precipitation
threat ending overnight. Much cooler readings are expected into
the weekend with dry conditions statewide as polar high pressure
settles into the upper Midwest. The relatively quiet weather will
persist into early next week with gradual moderation in
temperatures. Next chance of precipitation should arrive around
next week as upper low in northwest US moves toward the plains and
moisture returns to the region.


issued at 1251 PM CDT Wednesday may 27 2015

High pressure will be in control over Iowa through the forecast
period bringing VFR conditions to the taf locations. A light and
variable wind will become southerly this evening then increase in
speed after 28/14z. We will become more unstable through the day
Thursday but thunderstorms should hold off through the forecast


Dmx watches/warnings/advisories...none.



Short term...fab
long term...cogil

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